Comparing Apples with Frogs

Sir Peter Gluckman has written what I consider to be an eminently sensible and well-reasoned piece on climate change. As usual, the media have taken it out of context and made it to look like he has written some sort of diatribe against climate change skeptics, which does not appear to be Gluckman’s intention at all. In addition, the Herald has managed to cite the least well-reasoned portion of Gluckman’s piece in order to “prove” their point.

““A similar debate occurred about Aids, where a minority of scientists maintained for a long time that the disease was not caused by a virus.

““This view was manifestly wrong in the eyes of most scientists,” it says, “but nevertheless some distinguished scientists, albeit usually not experts in virology, took different views until the science became irrefutable. The political consequences of this denialism had tragic results in some African countries.””

Unfortunately, this part of Gluckman’s argument is not even comparing apple and oranges (at least they are both fruit), but is more like comparing apples and frogs.

Initially medicine and climate science would seem a little similar in their methods. Both tend to use statistical data to formulate their theories. Both are working with very complex systems. However, medicine then can properly verify or disprove those theories by experiment on the actual complex system (people!). Climatology continues to gather empirical data and come to a consensus of opinion.

Therefore the position of people who viewed the viral aetiology of AIDS with skepticism were (at the time) justified in doing so because medical science is expected to verify it’s theories. Prior to positive identification of HIV, skepticism was perfectly rational, even though it was proved wrong. Once experimental evidence was available, only conspiracy theorists still believed that AIDS was not caused by a virus.

The difference here is that climatologists cannot experiment on the complex system itself, they can only form an opinion based on the available data. The problem with this approach is that it is subject to great selectivity. People take data that fits in with the prevailing theory and “explain away” data that does not. Climate science therefore contains two groups of people who are interpreting the same data in different ways. Gluckman accuses the skeptics of being selective in their choices of data to expound or criticised, but the cloth cuts both ways, of course.

Whereas medical scientists will wait for experimental verification, climatologists will keep churning the debate with each new piece of data becoming a football in the argument, rather than a piece of a puzzle. The difference really is very sharp.

Unfortunately, politicians do not see this difference. They hear climate scientist say “the science is settled” or (in Gluckman’s case “the science is solid”), and they think that means the same as “the science is proven” – in the same sense as medical science, or worse, classical chemistry and physics, where results are not even statistically proven but absolute. Hence they formulate policy without realising that either side in the debate could be completely wrong and that the science is not “proven” at all.

It is possible that Anthropogenic Global Warming is happening, and that we are headed for a warm, damp time of it. But it is also very possible that humans have little to do with any warming effect and that the sole result of economic policies to reduce warming will be to reduce our economic capabilities of mitigating it’s effect on humans. Politicians should be aware that their actions will have large consequences and that shutting out one side of the debate on this can only be described as stupid.

Some of us older folk remember that we were heading into an ice age thirty years ago. I, for one, am upset that my igloo-building skills, so painstakingly learned, will apparently be no longer of use. And that science was “settled” too…

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